Axial rolls
10-26-2012, 01:49 PM
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Axial rolls
I have a Seagull Yak 54. I did the maiden flight the other day and have it trimmed for hands off level flight at about two thirds throttle. When the plane does a roll to the right, it is very axial. However, a roll to the left has a sort of corkscrew motion to it. Why does it do that and what do you adjust to correct it?
Thank you....... Mike
Thank you....... Mike
10-26-2012, 08:20 PM
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RE: Axial rolls
You'd be better off posting this question in one of the pattern or other aerobatics models forums. This is more about trimming the model than it is about anything to do with aerodynamics. The guys that know that sort of stuff will tell you to tweak this and that and suddenly the model will be doing fine.
10-27-2012, 10:48 AM
#4
RE: Axial rolls
It is possible that the engine has a little bit of left thrust..which is a total no-no.
I have a simple way to check the engine's thrust line in all axis. It's a 3/8" thick steel plate that bolts to the engine in place of the prop. It allows me to stand the plane on it's nose so that I can take measurements from key points on the airframe down to the table. Of course the table needs to be perfectly flat. A carpenter's square can also help while doing these checks.
Otherwise, if your airframe isn't straight and true you might be able to trim it for straight and level flight that favors a right roll, but not to the left. Go through the simple, step by step trim out procedures that some of the pattern guys have already posted after you have given your plane a real good visual check on a building table.
I have a simple way to check the engine's thrust line in all axis. It's a 3/8" thick steel plate that bolts to the engine in place of the prop. It allows me to stand the plane on it's nose so that I can take measurements from key points on the airframe down to the table. Of course the table needs to be perfectly flat. A carpenter's square can also help while doing these checks.
Otherwise, if your airframe isn't straight and true you might be able to trim it for straight and level flight that favors a right roll, but not to the left. Go through the simple, step by step trim out procedures that some of the pattern guys have already posted after you have given your plane a real good visual check on a building table.
10-27-2012, 05:48 PM
#5
Senior Member
RE: Axial rolls
ORIGINAL: BMatthews
You'd be better off posting this question in one of the pattern or other aerobatics models forums. This is more about trimming the model than it is about anything to do with aerodynamics. The guys that know that sort of stuff will tell you to tweak this and that and suddenly the model will be doing fine.
You'd be better off posting this question in one of the pattern or other aerobatics models forums. This is more about trimming the model than it is about anything to do with aerodynamics. The guys that know that sort of stuff will tell you to tweak this and that and suddenly the model will be doing fine.
However....One quick thing to check is whether your servos are travelling the same amount each way. Making certain that the aileron travel is the same each way is simple to check and should be the first thing one does after installing the servos
